This card takes its name from the Boss Rush, a common video game mode where the player faces a succession of bosses defeated in the earlier parts of a video game. The "rush" can be included in a single stage or parts of stages near the end of the game, usually directly before the last boss. Some games have boss rush as a necessary part, while in others it can also act as an extra challenge.
The concept of a Boss Rush involving the "B.E.S." monsters istaken from the Konami game Gradius, wherein a common element is a boss marathon consisting of about five bosses near the end of the game without any breaks between.